The Las Vegas infrasound array: Long term deployments for the characterization of urban environments

The Las Vegas Infrasound Array (LVIA) is a network of eleven infrasound sensors deployed from November 2019 through September 2022. While ambient infrasound noise in high and low-noise rural environments has been well characterized, little attention has focused on similar characterization in urban areas with presumed higher background noise levels. The LVIA long-term deployment provides an unprecedented opportunity to study urban infrasound and low frequency audio (20–500 Hz). In addition, large scale shutdowns due to the COVID-19 pandemic provide the ability to discriminate between background noise sources as closures reduced human-generated noise while natural signals remained stable. Within this presentation we will provide an overview of the LVIA installation, focusing on data quality. In addition, we will discuss comprehensive background noise models in urban regions, focusing on presenting probability density functions (PDFs) and median, 5th percentile, and 95th percentile amplitude values to evaluate variations in frequency and amplitude. We will summarize observed trends in background noise over time, highlighting sharp declines in acoustic power following COVID-19 shutdowns. Both sets of analyses will be combined to evaluate periodicities in urban acoustics throughout the city of Las Vegas. [ SNL is managed and operated by NTESS under DOE NNSA contract DE-NA0003525.]